Preparation for high alpha-Si3N4 phase silicon nitride

A phase silicon nitride and silicon nitride powder technology, which is applied in the field of high α-Si3N4 phase silicon nitride preparation, can solve the problems of high cost, low product quality, low output, etc., and achieves low cost, low energy consumption, high production low cost effect

Inactive Publication Date: 2008-09-24
山东硅苑新材料科技股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] (1) Liquid phase reaction method, gas phase reaction method, low output, high cost, unable to achieve large-scale production
[0005] (2) Carbothermal reduction silicon dioxide method, combustion synthesis method, the product quality of synthesis is low, can't obtain high-quality silicon nitride;
[0006] (3) The direct nitriding method of silicon powder is operated by keeping the nitrogen pressure constant. The synthesis of silicon nitride is carried out simply by controlling the temperature, and the β-Si cannot be controlled. 3 N 4 phase formation, resulting in α-Si in the product 3 N 4 low phase content

Method used

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  • Preparation for high alpha-Si3N4 phase silicon nitride
  • Preparation for high alpha-Si3N4 phase silicon nitride

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Experimental program
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Effect test

Embodiment 1

[0031] The high α-Si described in the present invention 3 N 4 Phase silicon nitride preparation method, carry out according to the following steps successively:

[0032] (1) Furnace by mixing silicon powder and silicon nitride powder evenly into briquettes, wherein the particle size of silicon powder is ≤15 μm, the particle size of silicon nitride powder is ≤2 μm, and the weight ratio of silicon powder and silicon nitride powder is: 100:8;

[0033] (2) Vacuum up to 2.0×10 -2 Pa;

[0034] (3) Charge hydrogen and nitrogen into the furnace, the charging volume ratio of hydrogen and nitrogen is: hydrogen: nitrogen=5: 100, and the firing pressure control is:

[0035] Before 1000℃, the air pressure is controlled at 10KPa;

[0036] 1000-1200℃, the air pressure is controlled at 10-30KPa (inflate when ≤10KPa, stop inflating when ≥30KPa);

[0037] 1200-1350°C, the air pressure is controlled at 20-40KPa (inflate when ≤20KPa, stop inflating when ≥40KPa).

[0038] The X-ray diffract...

Embodiment 2

[0040] The high α-Si described in the present invention 3 N 4 Phase silicon nitride preparation method, carry out according to the following steps successively:

[0041] (1) Furnace by mixing silicon powder and silicon nitride powder evenly into briquettes, wherein the particle size of silicon powder is ≤15 μm, the particle size of silicon nitride powder is ≤2 μm, and the weight ratio of silicon powder and silicon nitride powder is: 100:8;

[0042] (2) Vacuum up to 2.5×10 -2 Pa;

[0043] (3) Charge hydrogen and nitrogen into the furnace, the charging volume ratio of hydrogen and nitrogen is: hydrogen: nitrogen=7: 100, and the firing pressure control is:

[0044] Before 1000℃, the air pressure is controlled at 15KPa;

[0045] 1000-1200℃, the air pressure is controlled at 10-30KPa (inflate when ≤10KPa, stop inflating when ≥30KPa);

[0046] 1200-1350°C, the air pressure is controlled at 20-50KPa (inflate when ≤20KPa, stop inflating when ≥50KPa).

[0047] The X-ray diffract...

Embodiment 3

[0049] The high α-Si described in the present invention 3 N 4 Phase silicon nitride preparation method, carry out according to the following steps successively:

[0050] (1) Furnace by mixing silicon powder and silicon nitride powder evenly into briquettes, wherein the particle size of silicon powder is ≤15 μm, the particle size of silicon nitride powder is ≤2 μm, and the weight ratio of silicon powder and silicon nitride powder is: 10:1;

[0051] (2) Vacuum up to 1.5×10 -2 Pa;

[0052] (3) Charge hydrogen and nitrogen into the furnace, the charging volume ratio of hydrogen and nitrogen is: hydrogen: nitrogen=8: 100, and the firing pressure control is:

[0053] Before 1000℃, the air pressure is controlled at 20KPa;

[0054] 1000-1200℃, the air pressure is controlled at 10-30KPa (inflate when ≤10KPa, stop inflating when ≥30KPa);

[0055] 1200-1350°C, the air pressure is controlled at 20-60KPa (inflate when ≤20KPa, stop inflating when ≥60KPa).

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Abstract

The invention relates to a high Alpha-Si3N4 phase silicon nitride preparation method, which is carried out according to the following steps: silicon powder and silicon nitride powder are evenly mixed and pressed for charging; vacuum is pumped to (1.0-3.0)*10 <-2> Pa; hydrogen and nitrogen are filled in a stove, and the hydrogen and the nitrogen has the filling volume ratio that the ratio of the hydrogen and the nitrogen equals to (1-10): 100; burning pressure control is as follows: the pressure is controlled at 5-30Kpa before 1000 DEG C, the pressure is controlled at 10-30Kpa between 1000 DEG C and 1200 DEG C, and the pressure is controlled at 20-80Kpa between 1200 DEG C and 1350 DEG C. The phase content of the Alpha-Si3N4 is high; the energy consumption is low; the production cost is low; the Alpha-Si3N4 is suitable for mass production.

Description

technical field [0001] The invention relates to a high α-Si 3 N 4 The invention discloses a method for preparing phase silicon nitride, which belongs to the technical field of special ceramics. Background technique [0002] Silicon nitride is widely used in sliding and rolling bearing balls and seats under high contact stress conditions due to its good mechanical properties, high chemical stability, low density and good high temperature performance, thermal shock resistance and creep resistance. As well as structural ceramics working under high temperature and chemical corrosion conditions, refractory materials in the metallurgical industry, etc. [0003] At present, there are three main methods for manufacturing silicon nitride powder: [0004] (1) The liquid phase reaction method and the gas phase reaction method have low output and high cost, and cannot realize large-scale production. [0005] (2) Carbothermal reduction silicon dioxide method, combustion synthesis met...

Claims

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Application Information

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IPC IPC(8): C01B21/068
Inventor 高礼文樊震坤许业静刘天程范勇刘宝英刘德军
Owner 山东硅苑新材料科技股份有限公司
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